Welcome to Newark International ... Shopping Mall?

Anyone who's flown in the past 10 or 15 years has no doubt noticed the "mallification" of the world's airports, with retail stores and restaurants popping up in ever-greater abundance and sophistication. It's no longer uncommon to see high-end designer storefronts blur by as you sprint through the terminal to your flight.

As it turns out, these various retail outlets have not only become part of the airport experience, but, along with terminal services like parking, are also essential to the airports' bottom line.

In 2008, non-aviation operating revenue at U.S. airports was $7.5 billion, up 6.4 percent from 2007. That's as passenger volume fell 3.6 percent.

Breaking down that $7.5 billion shows that parking services is the biggest revenue generator, at $3 billion. Rental car operations kick in another $1.5 billion, while retail brings in $639 million and food and beverage services contribute $569 million.

As the travel sector continues to struggle and shrink, this expanding revenue base will come in handy.

Readers, do you shop at the airport? Or do you think the preponderance of retail and restaurants is an eyesore? Leave a comment below with your thoughts. Thanks!